The fabled Pretzel lens?

So I was doing some photo gear housekeeping this evening and I came across a large brass lens---5-1/4'' long x 4-3/4'' wide and about 12'' focal length marked
McIntosh Stereopticon Co.
Chicago
H-15
Could this be one of them fandangled swirly lens thangs?
Does anyone here shoot with a "McIntosh?"